Assertion: `Ag` and `Au` are extracted by leaching the ores with a dilute solution of `NaCN`.
Reason: Impurities associated with these ores dissolve in `NaCN`.

Options

A. If both (A) and ( R) are correct and ( R) is the correct explanation of (A).
B. If both (A) and ( R) are correct, but ( R) is not the correct explanation of (A).
C. If (A) is correct, but ( R) is incorrect.
D. If (A) is incorrect, but ( R) is correct.

Answer

C

Explanation

Correct reason : `Ag` and `Au` dissolve in `NaCN` forming a soluble complex.
`4Ag+8NaCN+2N_(2)O+O_(2)rarr4Na[Ag(CN)_(2)]+4NaOH`
`4Au+8NaCN+2H_(2)O+O_(2)rarr4Na[Au(CN)_(2)]+ 4NaOH`.